Apparatus for manufacturing adhesive tape products

ABSTRACT

Apparatus for making pervious pressure-sensitive adhesivecoated fabric from thermoplastic adhesive and a fabric backing sheet comprising a moving surface for supporting a pressuresensitive adhesive film, a multiplicity of fixed plough elements transversely spaced from one another with their free ends continuously maintained in pressure contact with said movable surface for separating it into a multiplicity of continuous transversely spaced strips each of substantially greater thickness at its edges than in its central portion and spaced from one another by continuous openings, said surface carrying said adhesive film past said plough elements causing lateral flow of said adhesive moving past said plough elements continuously to form said openings by displacing film material from said openings laterally to the edges of the strips, creating said openings and providing said greater thickness of film at the edges of said strips continuously therealong and means for moving said fabric backing into contact with and thereafter pressing the unsupported surface of said strips while separated by said openings and while supported on their other side by said surface into contact with the surface of said fabric to bond said adhesive strips to said fabric by penetrating said fabric with the material of said strips to a greater degree at the edges thereof providing a greater degree of bonding along the edges of said strips throughout their length while maintaining said openings in their open state to provide a permanently porous pressure-sensitive, adhesive-coated fabric.

l nit States Patent [72] Inventor Joseph C. Komp Bowling Green, Ky. [21] Appl. No. 5,310 [22] Filed Jan. 23, 1970 [45] Patented Dec. 21, 1971 [73] Assignee The Kendall Company Boston, Mass.

Original application Dec. 11, 1968, Ser. No. 786,815, now Patent No. 3,523,859, dated Aug. 11, 1970, which is a continuation of application Ser. No. 437,813, Mar. 8, 1965, now abandoned. Divided and this 1 application Jan. 23, 1970, Ser. No. 5,310

[54] APPARATUS FOR MANUFACTURING ADHESIVE TAPE PRODUCTS 9 Claims, 10 Drawing Figs.

[52] 11.5. C1 118/261 [51] 1nt.Cl B05c 11/10 [50] Field of Search 156/290,

Wangner 118/102 X ABSTRACT: Apparatus for making pervious pressure'sensitive adhesive-coated fabric from thermoplastic adhesive and a fabric backing sheet comprising a moving surface for supporting a pressure-sensitive adhesive film, a multiplicity of fixed plough elements transversely spaced from one another with their free ends continuously maintained in pressure contact with said movable surface for separating it into a multiplicity of continuous transversely spaced strips each of substantially greater thickness at its edges than in its central portion and spaced from one another by continuous openings, said surface carrying said adhesive film past said plough elements causing lateral flow of said adhesive moving past said plough elements continuously to form said openings by displacing film material from said openings laterally to the edges of the strips, creating said openings and providing said greater thickness of film at the edges of said strips continuously therealong and means for moving said fabric backing into contact with and thereafter pressing the unsupported surface of said strips while separated by said openings and while supported on their other side by said surface into contact with the surface of said fabric to bond said adhesive strips to said fabric by penetrating said fabric with the material of said strips to a greater degree at the edges thereof providing a greater degree of bonding along the edges of said strips throughout their length while maintaining said openings in their open state to provide a permanently porous pressure-sensitive, adhesive-coated fabric.

PATENTEDDECZYM 3,628,502

SHEET 1 [IF 2 PATENTEUUECZI rem 3,628,502

SHEET 2 BF 2 APPARATUS FOR MANUFACTURING ADHESIVE TAPE PRODUCTS This is a division of application Ser. No. 786,815, filed Dec. 11, 1968, now US. Patent No. 3,523,859, granted Aug. II, 1970, which was in turn a continuation of application Ser. No. 437,813, filed Mar. 8, 1965, now abandoned. Its invention relates to novel pervious pressure-sensitive adhesive tape products and the like, as well as to novel methods and apparatus for manufacturing same.

Pressure-sensitive adhesive tapes of the type having a woven or other fabric backing with a pressure-sensitive adhesive film adhered to one side thereof have been in wide use for many years, although it has long been known that their lack of air permeability was disadvantageous, particularly in the case of hospital and athletic tapes, in that it caused skin maceration because moisture was unable to pass through the impervious adhesive film. Although attempts have heretofore been made to remedy the situation by providing an adhesive tape having openings therein, such tapes or their methods and apparatus of manufacture have been deficient in one or more respects, for example, by introducing contaminating materials during the formation of the tape, or causing manufacturing difficulties which increased the cost of the tape to an uneconomic degree.

Accordingly, it is the major object of the present invention to produce a novel pervious adhesive tape product which not only is free of contaminating materials and of manufacturing difficulties as well, but which has a high degree of air and moisture permeability even when used in more than one layer.

It is another object of the invention to provide novel methods for manufacturing pervious adhesive tapes and the like, which methods are economical both in cost and efficiency.

It is still another object of the invention to provide novel apparatus useful in the manufacture of such tapes.

Other objects and features of the present invention will become apparent from the following detailed description of preferred embodiments thereof, together with the accompanying drawings, wherein:

FIG. I is an isometric view of an adhesive tape according to the present invention;

FIG. 2 is an isometric view of an adhesive tape according to the invention somewhat modified from that of FIG. 1;

FIG. 3 is an enlarged cross section of a portion of the tape of FIGS. I and 2;

FIG. t is a somewhat diagrammatic side elevation of ap paratus according to the invention for carrying out the process thereof; a

FIG. 5 is a detail cross section of a portion of the apparatus of FIG. 4;

FIG. 6 is an isometric detail view of a portion of the apparatus of FIG. 4, showing one aspect of the process of the invention;

FIG. 7 is a cross section ofa portion of the apparatus of FIG. 4, taken on the line 77 thereof, showing another aspect of the process of the invention;

FIG. 0 is a plan view, partly broken away, of the apparatus of FIG. 4;

FIG. 9 is an end elevation, partly broken away, of the apparatus of FIG. d, and

FIG. 10 is an enlarged cross section of the apparatus of FIG. 4 taken on line 10-10 ofFIG. 8.

Referring to FIGS. 1 and 3, the novel adhesive tape of the invention includes a pervious backing fabric sheet, generally designated 20, with a plurality of continuous adhesive film strips 12, MI, 16 and 18, each of uniform width and transversely spaced from one another by openings 13, 15, I7 and I9, respectively, said strips being pressure united to sheet 20. The sheet 20 may be of any suitable pervious material, preferably a fabric woven of natural or synthetic textile fibers having warp yarns 21 and filling yarns 22. Pervious nonwoven backing sheets of textile or other fibers or other types of pervious backing sheets may be used but the invention as to certain of its aspects is particularly applicable to woven fabric backing sheets. The adhesive film strips I2, I4, 16 and 118 are composed of a tacky, cohesive rubbery material, the composition of which is well known in the art, with flat smooth calendered outer surfaces 24 and inner surfaces having edge portions 26 of greater film thickness than the central portions 27 therebetwcen. With such novel configuration, the adhesive film edge portions 26 penetrate the yarn 21, 22 of backing sheet 20 a greater depth than do the central portions 27, thus providing a greater degree of bonding between the strips along their edges throughout the entire length thereof. This provides a high degreeof resistance to delamination along the edges of the strips as might otherwise occur when pulling the tape from a roll thereof, and such is achieved with the structure of the tape of the present invention without utilizing an unusually thick film throughout the transverse dimension of the strips, rather only at the edges thereof.

As shown in FIG. 2, the strips preferably extend in a sinuous pattern of limited amplitude preferably more than about the width of a strip transversely back and forth across at least one of the warp yarns 21, the strips l2, 14', 16, and I8 of FIG. 2 being of a sinusoidal pattern, with an amplitude slightly more than the width of a strip and of a relatively short wavelength of about an inch, although much longer wavelengths of the order of several yards may be utilized. With a woven backing, and an amplitude sufficient for the traversing of at least one warp yarn by the openings 13', 15, 17' and 19, sinuously extend ing strips effectively prevent continuous raveling of a yarn at the edge of a tape, which might otherwise occur because of the slitting into narrow strips for packaging cannot be carried out without causing severing of one or more warp yarns sufficient to initiate raveling whenever the slitting occurs along a slot wherein the yarns are not bonded to the backing as frequently occurs.

The tape of either FIG. 1 or FIG. 2 is utilized in the usual manner, conventionally in the form of an indeterminate long length wound up onto a roll, from which it may be dispensed in short lengths or may be wound in several overlapping turns about a portion of a human limb, for example, In such a case, the continuous openings of the tape of the present invention provide a unique advantage, since with a strip width of about one-eighth to one-fourth inch and opening width of 0.015 to 0.075 inch, overlapping turns with successive turns at but a slight angle will cause the continuous slots of the successively applied turns to cross one another so to provide direct adhesive openings through the tape at each such crossing. This greatly improves tape permeability, reducing skin maceration even with multiple layers of tape.

In brief, the novel method of making the tape of FIG. I according to the present invention comprises providing a pressure-sensitive adhesive film supported on a moving surface and then separating the film, while the :film is supported on the surface, into a multiplicity of continuous transversely spaced strips, each of uniform width throughout its length and of substantially greater thickness at its edges than in its central position and spaced from one another by continuous openings each of uniform width through its length. This is uniquely accomplished according to the invention by causing lateral flow of the adhesive throughout the depth of the film at each of a plurality of discrete fixed transversely spaced positions corresponding to the openings continuously to form said openings by displacing film material from said positions laterally to the edges of the strips as the film moves past said positions, creating the openings and providing a greater thickness of film at the edges of the strips continuously therealong. Thereafter, the unsupported side surface of the strips, while separated by said openings and while supported on their other side surfaces by the moving surface is pressed into contact and pressure united with the surface of the pervious fabric to bond the adhesive strips to the fabric by penetrating the fabric with the material of the strips to a greater degree at the strip edges, while avoiding closing of the openings.

Apparatus for carrying out the above-described process and modifications thereof as hereinafter described is shown in FIGS. 4 through 10.

In general, it comprises a three roll stack of rotating calender rolls, upper roll 32, intermediate roll 34 and lower roll 36, driven by suitable means (not shown) known to the art. Intermediate roll 34 is heated to a greater degree and is rotated faster than is upper roll 32, so that the upper and intermediate rolls comprise a pair of rotating calender rolls having heated, imperforate, essentially nonyielding surfaces for calendering a mass M of heat softenable thermoplastic adhesive, while in a heat-softened state, into a pressure sensitive adhesive Film F. The surface of intermediate roll 34 is maintained at a temperature sufficiently high to keep the film supported thereon in an inelastic, flowable heat softened condition. Lower roll 36 is rotated at the same speed as intermediate roll 34 and provides a moving surface for carrying backing sheet B into contact with the adhesive film supported on the surface of intermediate roll 34 and pressure uniting it with said backing sheet, providing a pressure-sensitive adhesive coated fabric L which is thereafter led from lower roll 36 for cooling, slitting and packaging. The apparatus as above set forth, being well known and long used in the art, need not be further described.

According to the present invention, means are provided for separating film F, while it is supported on the surface of intermediate roll 34, into a multiplicity of strips S transversely spaced from one another in a direction parallel to the roll axis to provide discrete openings therebetween. Such means comprises a multiplicity of fixed plough elements, generally designated 40, transversely spaced across intermediate roll 34, said plough elements having shanks arranged at a trailing angle to the surface of roll 34 with slightly arcuate generally flat bottom surfaces are generally tangential to the surface of roll 34 and in contact therewith. Preferably plough elements 40 are provided with side surfaces 44 perpendicular to the roll surface converging into an edge 46 perpendicular to the roll axis for presentation to the film F passing therearound, and may be generally square in cross section with one of its diagonals along the direction of film advances, as shown in H0. 6, although it is contemplated that other plough elements may be about 0.025 to 0.l in their transverse dimensions, and be spaced about one-eighth to three-eighth inch.

The multiplicity of plough elements is supported in side by side relationship in a pair ofclamps, upper clamp 52 and lower clamp 54, extending across roll 34, the latter being provided with an electric heater element 55, one end of such clamps and of the apparatus being shown in FIGS. 8 and 9. A plurality of thumb screws 53 are provided for holding upper clamp 52 firmly against lower clamp 54 to retain plough elements 40 therebetween.

Lower clamp 54 with upper clamp 52 and plough elements 40 are supported and guided both for transverse reciprocating movement of limited amplitude generally axially of roll 34 to produce the sinuous openings and to prevent grooving of the roll surface and for radial movement of roll 34, so that plough elements 40 may be maintained in pressure contact with said roll, or alternatively, may be moved to an inoperative position with their bottoms spaced from the roll surface so as to clear any film thereon.

To make this possible, lower clamp 54 is mounted in subbase 56 for limited sliding movement in direction radially of intermediate roll 34, such movement being produced by a double-acting hydraulic cylinder 60 mounted on subbase 56 and having its piston 62 mounted at its free end on lower clamp 54 by cylindrical block 58. A valve 64 is provided for alternatively connecting the opposite chambers of said cylinder to a source of hydraulic pressure at 66 or exhaust at 67.

Subbase 56 is itself mounted on machine base 70 for limited reciprocating movement in a direction generally axially of intermediate roll 34 by means of supporting and guiding rollers 72, 73, 74, 75, 76, the reciprocating movement being provided by an eccentric mechanism driven by motor 84 mounted on base 70, such mechanism consisting of a crank arm 86 on the motor shaft carrying a crank roller 87 received in a cooperating vertically slotted member 88 mounted on subbase During operation of the apparatus of the invention, with the calender rolls 32, 34, 36, being rotated, motor 84 preferably operated to reciprocate plough elements 40 to a limited extent, say about oneeighth to three-eighth inch, roughly the same as the plough element spacing, and valve 64 operated so that hydraulic cylinder 60 will continuously maintain the bottom surfaces 42 of plough elements 40 in pressure contact with the surface of roll 34, the apparatus of the invention will continuously produce a permanently pervious pressure-sensitive adhesive coated fabric, such as that shown in F IG. 2, for example, upon providing an adhesive mass M and fabric backing B to such apparatus.

More specifically, the upper and intermediate calender rolls 32 and 34, respectively, operate on the mass M of adhesive material to calender it into a pressure sensitive film of perhaps 3 to 10 mils thickness, such film being supported and carried on the surface of the intermediate roll 34 which roll is heated to a higher temperature than is upper roll 32 to prevent adherence of the film to the latter and to maintain it while on roll 34 in an inelastic, flowable, heat-softened condition.

' With the film so maintained and supported on the surface of roll 34, it is advanced to the reciprocating but rotatably fixed plough elements 40 which have their bottom surfaces 42 in running contact with the moving surface of said roll. As illustrated with particular clarity in FIGS. 5 and 6, the pointed leading edges 46 of the plough elements separate the continuous film F advancing thereto into a plurality of continuous strips S, each of unifonn width or about one-eighth to threeeighth inch throughout its length and of substantially greater thickness at its raised edges 26 than in its central portion 27, the openings between such strips also extending continuously and being of uniform width of about 0.015 to 0.075 inch, throughout their length slightly less than the dimension of the plough element 40 by which it was formed. Both the strips S and the openings therebetween preferably extend somewhat sinuously with respect to the direction of their advance with roll 34, by reason of the preferred limited reciprocating movement ofplough elements 40.

More specifically as to plough elements 40, it is preferable that they be maintained at a temperature, by means of heater element 55, which need be but say 50 to 59 F. higher than the temperature of the surface of roll 34 which may be at a temperature of about 200 F. or somewhat higher. With such a slight temperature difference, not enough to cause deterioration of the film and by reason of the trailing angle at which edge 46 is presented to the film, accumulation of film material on the plough elements 40 does not occur. Thus, the plough elements 40 are enabled to operate indefinitely without the use of release agents which cause contamination of the film, to cause lateral flow of the adhesive moving past them continuously to form openings in the film by removing film from the area of the openings and displacing it laterally to the edges of the strips, providing the unique raised edges providing greater film thickness thereat as is characteristic of the invention.

The film strips S so produced, still carried on the surface of roll 34, are then advanced into contact with and pressure united to a fabric backing strip B carried on the surface of lower roll 36 at the same speed, FIG. 7 showing the condition of the two laminates just prior to their being so pressure united and FIG. 3 the condition thereafter. More specifically, and as shown by said FlGS., the surfaces of the adhesive strips not in contact with intermediate roll 34, that is, the surface having its edge portions 26 raised with respect to its central portion 27, is pressed into contact with one surface of the backing sheet B, while the other surfaces of both strips S and backing sheet B are supported by its smooth surfaces of rolls 34 and 36, respectively. This provides the unique penetration of the yarns of the backing sheet to a greater degree at the edges 26 of the strips S, while maintaining the openings, and while maintaining the other surface of the film, its roll contacting surface 24, in smooth flat calendered condition for the most effective functioning of the pressure-sensitive adhesive action thereof.

After such pressure uniting to provide the permanently pervious pressure-sensitive adhesive tape of the invention, it is removed from the surface of lower roll 36 for suitable cooling, slitting and packaging as desired.

The plough element dill need not scrape the surface of the roll M completely clean of adhesive in the slots separating the strips 5. in operation, it has been observed that a very thin, practically invisible, veillike layer of adhesive may span the slots in contact with the surface of the roll 3 Such thin layer advantageously may serve as a lubricant between the bottom surface t}; of plough element 40 and the surface of intermediate roll 34!, serving to reduce wear on these surfaces. The thin film of adhesive may either remain on the surface of the roll Ml to be returned to the bulk mass M after the pressure laminating step at the nip between rolls 34! and 36 or be transferred to the fabric during the laminating step. The thin film ruptures either during the laminating step or subsequent thereto, at which time it ruptures or contracts to a highly porous and open state that does not detract from the natural porosity of the backing in the slot areas. in some instances, the adhesive in the slot areas may be desirable in serving to bind together fibers cut in the slot areas upon slitting. ln appears that the formation of the lubricating thin layer of adhesive depends upon elements are urged toward the surface of the roll 3d. The tendency for the adhesive in the slot area to transfer to the backing is greater in the case of softer adhesives and smaller slot widths.

I claim:

l. Apparatus for making pervious pressure-sensitive adhesive-coated fabric from thermoplastic adhesive and a fabric backing:

comprising a movable surface for supporting said pressuresensitive adhesive a multiplicity of fixed plough elements tranversely spaced from one another with their free ends continuously maintained in pressure contact with said movable surface for separating said film while said film is supported on said surface into a multiplicity of continuous transversely spaced strips of substantially greater thickness at its edges than in its central position and spaced from one another by continuous openings said surface carrying said adhesive film past said plough elements causing lateral flow of said adhesive moving past said plough elements continuously to form said openings by displacing film material from said slots laterally to the edges of said strips creating said openings and providing said greater thickness of film at the edges of said strips continuously therealong and means for moving said fabric backing into contact with and thereafter pressing the unsupported surface of said strips while separated by said openings and while supported on their other side by said surface into contact with the surface of said fabric to bond said adhesive strips to said fabric by penetrating said fabric with the material of said strips to a greater degree at the edges thereof providing a greater degree of bonding along the edges of said strips throughout their length while avoiding closing of said openings and maintaining said openings in their open state to provide a permanently porous pressure-sensitive, adhesive-coated fabric.

2. Apparatus as claimed in claim 1 wherein said supporting surface is a roll providing an imperforate, essentially nonyielding surface.

3. Apparatus as claimed in claim ll wherein said plough elements are provided with converging surfaces extending perpendicular to the said movable surface and converging into an edge for presentation to said film passing therearound.

l. Apparatus as claimed in claim ll wherein said plough elements are reciprocated generally axially ofsaid roll.

5. Apparatus as claimed in claim ll wherein said plough elements are supported at a trailing angle with respect to said roll.

ti. Apparatus for making previous pressure-sensitive adhesive from thermoplastic adhesive:

comprising a rotatable roll having a smooth movable surface for supporting said pressure-sensitive adhesive and a multiplicity of fixed plough elements transversely spaced from one another and having surfaces converging into an edge perpendicular to the axis of said roll at a trailing angle to said roll surfaces for presentation to an advancing film on said roll surface, said elements having flat bottom surfaces continuously maintained in running pressure contact with said movable roll surface for separating said film while said film is supported on said surface into a multiplicity of continuous transversely spaced strips and of substantially greater thickness at its edges than in its central position and spaced from one another by continuous openings said surface carrying said adhesive film past said plough elements causing lateral flow of said adhesive moving past said plough elements continuously to form said openings by displacing film material from said slots laterally to the edges of said strips, said plough elements creating said openings and providing said greater thickness of film at the edges of said strips continuously therealong.

7. Apparatus as claimed in claim t5 further including means including a movable surface for moving a fabric backing into contact with and thereafter pressing the unsupported surface of said strips while separated by said openings and while supported on their other side by said surface into contact with the surface of said fabric to bond said adhesive strips to said fabricby penetrating said fabric with the material of said strips to a greater degree at the edges thereof providing a greater degree of bonding along the edges of said strips throughout their length while avoiding closing of said openings and maintaining said openings in their open state to provide a permanently porous pressure-sensitive, adhesive-coated fabric.

8. Apparatus for making pervious pressure-sensitive adhesive-coated fabric from heat softenable thermoplastic adhesive and a woven fabric backing comprising a pair of rotating calender rolls having heated,

imperforate, essentially nonyielding surface, for calendering said adhesive while in a heat-softened state into a pressure-sensitive adhesive film, one of said rolls supporting said adhesive film on the moving surface thereof a multiplicity of fixed plough elements transversely spaced across said supporting roll and in contact with its surface for separating said film into a plurality of continuous strips of substantially greater thickness at its edges than in its central position spaced from one another by continuous openings in a generally axial direction along said roll while said film is supported on said roll said plough openings having shanks supported at a trailing angle with respect to the supporting surface of said roll with free ends having generally flat bottoms at an angle to said shanks means for continuously maintaining said bottoms in pressure contact with the said supporting surface of said rolls means for reciprocating said plough elements generally axially of said roll said roll surface carrying said adhesive film, this being moved past said plough elements said plough elements causing lateral flow of said adhesive moving past said plough elements continuously to form said openings by removing film material therefrom and displacing said film material laterally to the edges of said strips, providing said greater thickness of film at said edges continuously therealong and roll means for thereafter continuously pressing one side of said strips separated by said openings while the other side is supported by said surface into contact with the one surface of a pervious fabric while the other surface is supported by said roll means continuously to bond said adhesive film to said backing fabric as said strips and fabric advance into contact, by penetrating said backing sheet with said film 3,628,502 7 p 8 to a greater degree at said edges providing a greater porous pressure-sensitive,adhesive-coated fabric. degree of bonding along the edges of said strip 9. Apparatus as claimed in claim 8 providing means for throughout their length while avoiding closing of 'said m in aining the temperature of said plough elements at a openings in said adhesive m d maintaining said higher temperature than that of said adhesive film supporting openings in their open state and maintaining a smooth flat surface' calendered adhesive surface to provide a permanent'iy Patent No.

UNITED STATES PATENT OFFICE Dated December 21, 1971 Column may be 3, line used as line Column 5,

Column 5, line Signed and (SEAL) Attest:

EDWARD M.FLETCHER, JR Attssting Officer Inventor(s) Joseph Komp It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

31, after "surfaces" insert 42 at an angle such that said bottom surfaces--;

38', after "elements" insert --configurations well. The plough elements--;

21, "In" should be -It-;

23, after "upon" insert --the softness of the mass and the pressure at which the plough--.

sealed this 13th day of June 1972.

ROBERT GOTISCHALK Commissioner of Patents FORM PO-1050(10-69) USCOMM-DC 60376-P69 I 0.5 GOVUIHHINY PR NTING OFIICE: llll (7-!!6-314 

2. Apparatus as claimed in claim 1 wherein said supporting surface is a roll providing an imperforate, essentially nonyielding surface.
 3. Apparatus as claimed in claim 1 wherein said plough elements are provided with converging surfaces extending perpendicular to the said movable surface and converging into an edge for presentation to said film passing therearound.
 4. Apparatus as claimed in claim 1 wherein said plough elements are reciprocated generally axially of said roll.
 5. Apparatus as claimed in claim 1 wherein said plough elements are supported at a trailing angle with respect to said roll.
 6. Apparatus for making previous pressure-sensitive adhesive from thermoplastic adhesive: comprising a rotatable roll having a smooth movable surface for supporting said pressure-sensitive adhesive and a multiplicity of fixed plough elements transversely spaced from one another and having surfaces converging into an edge perpendicular to the axis of said roll at a trailing angle to said roll surfaces for presentation to an advancing film on said roll surface, said elements having flat bottom surfaces continuously maintained in running pressure contact with said movable roll surface for separating said film while said film is supported on said surface into a multiplicity of continuous transversely spaced strips and of substantiallY greater thickness at its edges than in its central position and spaced from one another by continuous openings said surface carrying said adhesive film past said plough elements causing lateral flow of said adhesive moving past said plough elements continuously to form said openings by displacing film material from said slots laterally to the edges of said strips, said plough elements creating said openings and providing said greater thickness of film at the edges of said strips continuously therealong.
 7. Apparatus as claimed in claim 6 further including means including a movable surface for moving a fabric backing into contact with and thereafter pressing the unsupported surface of said strips while separated by said openings and while supported on their other side by said surface into contact with the surface of said fabric to bond said adhesive strips to said fabric by penetrating said fabric with the material of said strips to a greater degree at the edges thereof providing a greater degree of bonding along the edges of said strips throughout their length while avoiding closing of said openings and maintaining said openings in their open state to provide a permanently porous pressure-sensitive, adhesive-coated fabric.
 8. Apparatus for making pervious pressure-sensitive adhesive-coated fabric from heat softenable thermoplastic adhesive and a woven fabric backing comprising a pair of rotating calender rolls having heated, imperforate, essentially nonyielding surface, for calendering said adhesive while in a heat-softened state into a pressure-sensitive adhesive film, one of said rolls supporting said adhesive film on the moving surface thereof a multiplicity of fixed plough elements transversely spaced across said supporting roll and in contact with its surface for separating said film into a plurality of continuous strips of substantially greater thickness at its edges than in its central position spaced from one another by continuous openings in a generally axial direction along said roll while said film is supported on said roll said plough openings having shanks supported at a trailing angle with respect to the supporting surface of said roll with free ends having generally flat bottoms at an angle to said shanks means for continuously maintaining said bottoms in pressure contact with the said supporting surface of said rolls means for reciprocating said plough elements generally axially of said roll said roll surface carrying said adhesive film, this being moved past said plough elements said plough elements causing lateral flow of said adhesive moving past said plough elements continuously to form said openings by removing film material therefrom and displacing said film material laterally to the edges of said strips, providing said greater thickness of film at said edges continuously therealong and roll means for thereafter continuously pressing one side of said strips separated by said openings while the other side is supported by said surface into contact with the one surface of a pervious fabric while the other surface is supported by said roll means continuously to bond said adhesive film to said backing fabric as said strips and fabric advance into contact, by penetrating said backing sheet with said film to a greater degree at said edges providing a greater degree of bonding along the edges of said strip throughout their length while avoiding closing of said openings in said adhesive film and maintaining said openings in their open state and maintaining a smooth flat calendered adhesive surface to provide a permanently porous pressure-sensitive, adhesive-coated fabric.
 9. Apparatus as claimed in claim 8 providing means for maintaining the temperature of said plough elements at a higher temperature than that of said adhesive film supporting surface. 